Battery chargers for outdoor use need some protection against rain and condense water as well as melting snow, i.e. they need to be provided with features which prevent water from penetrating through the air vents into the electrical components of the charger inside the housing. Battery chargers for indoor use also need protection, because batteries used outdoor can contain rain water and condense water and/or snow on the outside as well as on the inside. Water from the battery placed on top of the battery charger can then drop through the air vents in the charging space down onto the electrical components inside the housing of the charger. A problem with water may also arise if the fan sucks water through the air vents into the charger.
The usual solution is thereby to locate the air vents in an area separated from the electrical components of the charger and yet close to the electrical components in order to provide satisfactory cooling of the battery under charging and of said electrical components. This compromise has led to constructions, the operation of which hitherto has not been the best.